PyCharm Run and Debug

PyCharm provides powerful running and debugging tools to help developers efficiently execute and troubleshoot Python code issues. This section will detail environment configuration, script running, and debugging techniques.

Configure the Runtime Environment

Set the Python Interpreter

Open the Interpreter Settings:Settings → Project → Python Interpreter (Windows/Linux: Ctrl+Alt+S, Mac: ⌘,).

Select the Interpreter:

  • Virtual Environment(Recommended):Virtualenv / Conda / Pipenv

  • System Interpreter: Directly use the installed Python

  • Remote Interpreter: Connect to a server or Docker environment

Install Dependency Packages:

  • In the interpreter interface, click+Search and install packages (e.g.,requests）

  • Or run through the terminalpip install package_name

Configure Run Parameters

Open the Run Configuration:

  • Top toolbar →Run → Edit Configurations（Run → Edit Configurations）

  • Or click the configuration dropdown next to the Run button

Add a Python Configuration:Click + → Select Python

Key Parameters:

  • Script Path: Select the.pyfile to execute

  • Parameters: Enter command-line parameters (e.g.,--port 8000）

  • Working Directory: Set the current directory when the script runs

  • Environment Variables: Add custom environment variables (e.g.,PYTHONPATH）

Save the Configuration:Click Apply → OK.

Run Python Scripts

Run a Single File

Method 1: Right-click Run：

  • Right-click in the editor →Run 'filename'（Run 'filename'）

Method 2: Toolbar Run：

  • Click the green Run button ▶️ in the top toolbar

Method 3: Shortcut Run：

  • Shift + F10(Run the current file)

  • Ctrl + Shift + F10(Run the currently edited file)

Run Modules (e.g., Flask/Django)

Configure Module Running:In the Run Configuration, select the module name instead of the script path.

For example:

  • Module name：flask

  • Parameters：run --port=5000

Run a Module with Parameters:

# 例如运行 Django 开发服务器
python manage.py runserver 0.0.0.0:8000

In the "Parameters" field of the Run Configuration, enter: runserver 0.0.0.0:8000

Debug Code

Set Breakpoints

Add a Breakpoint：

  • Click to the left of the line number (a red dot appears)

  • Right-click a breakpoint to set conditions (e.g.,x > 10）

Breakpoint Types：

  • Line Breakpoint: Pause at the specified line

  • Exception Breakpoint: Pause when an exception is thrown (运行 → 查看断点 → 添加 Python 异常断点）

Start Debugging：

  • Click the toolbar's🐞 Debugbutton

  • or the shortcut keyShift + F9

Variable Monitoring (Watches)

View Variables：

  • After debugging starts, in the变量（Variables）panel, view the variable values of the current scope

  • Double-click a variable to edit its value (for temporary testing)

Add Watch：

  • In监视（Watches）In the panel, click+

  • Enter a variable name or expression (e.g.,len(items)）

Debug Control Operations

OperationShortcut (Win/Linux)Shortcut (Mac)Description
Step OverF8F8Execute the current line without entering the function
Step IntoF7F7Enter the function to debug
Step OutShift + F8⇧ + F8Finish executing the current function and return to the call site
ResumeF9⌘ + F8Continue running until the next breakpoint
StopCtrl + F2⌘ + F2Terminate the debugging session

Debug Console

Interactive Debugging：

  • During debugging, you canDebug Consoledirectly execute Python code

  • For example: temporarily call functions or modify variables

  • Evaluate Expression：

    • Select code → Right-click →评估表达式（Evaluate Expression）

    • or the shortcut keyAlt + F8

    Advanced Debugging Tips

    Remote Debugging

    Configure a Remote Interpreter：

    • 文件 → 设置 → Python 解释器 → 添加远程解释器

    • Supports SSH, Docker, and Vagrant

    Debug Remote Code：

    • Breakpoints and debugging operations are the same as local debugging

    Multi-Process Debugging

    Child Process Debugging：

    • In the Run Configuration, check在子进程中调试（Debug child processes）

    • Applicable tomultiprocessingorsubprocessscenarios

    Attach to Process：

    • 运行 → 附加到本地进程（Attach to Local Process）

    • Select a running Python process

    Troubleshooting Common Problems

    Q1: Breakpoints not taking effect?

    • Check whether the interpreter matches the project environment

    • Ensure the code has been saved (Ctrl + S）

    • Check whether the breakpoint is disabled (the breakpoint icon is gray)

    Q2: How to debug unit tests?

    • Right-click in the test file →Debug 'test name'

    • Or usepytest / unittesta dedicated run configuration

    Q3: Variables display "Unknown" during debugging?

    • Optimize the code structure to avoid overly complex expressions

    • UseWatchesto manually add watch variables

    Debug Shortcuts

    Scenario Operation
    Quickly run the current file Shift + F10
    Start debugging Shift + F9
    Conditional breakpoint Right-click the breakpoint → Set condition
    View variable values When debugging, in theVariablespanel, view
    Temporarily execute code Enter commands in the Debug Console
    Multi-Process Debugging Check in the Run ConfigurationDebug child processes
    Other Extensions